set always modified immediately after opening?? [solved but still confusing]

[jdd]

I've run into a strange thing, wondering if anyone else has seen this before:

I have a set that always has an undo entry and a modification marker immediately after I open it. Something is modifying the input gain of ... something. Everything seems fine otherwise, but it seems very weird.

Has anyone seen anything like this before? Is there any way for me to track down exactly what has been modified without staring intently at every single parameter in my track?

Relevant and maybe not as relevant info:

I'm on Windows 10
There are VST instruments in use
I don't think I have any, eg, max LFOS (edit: this was a lie I have one on a frozen track, but it's there in the sets that aren't modified on open)
I have earlier versions of the set that this doesn't happen with
It happens consistently, saving -> reopening, undoing -> saving -> reopening, or doing a bunch of work and then saving all leave me with a set that has been touched by a ghost on open

[[jur]]

Could be a M4L device, or a VST (I know it often happens with some NI stuff, but probably with others too).
Unfortunately you'll probably need to track this down painstakingly.

[jdd]

Ok so I figured out how to remove the behavior but I don't know why it's happening:

I had a couple max lfos mapped to knobs on a frequency shifter on an audio effect rack in a midi track. The track was frozen.

Those knobs also had midi mappings defined for them from before I had decided to use LFOs here. Unfreezing the track, removing the midi mappings for the knobs, and refreezing makes the change go away on open.

The controller I mapped isn't plugged in, and it's the only one I use on the channel they were mapped to so I'm confused as to why or how removing the mapping stopped a value from being changed on a knob on a frozen track but software is messy.

Edit: I really don't understand why this worked because the midi mappings and the LFO mappings are present in earlier versions of the set where this weird behavior doesn't happen but OK I accept my fate

[[jur]]

That'd be interesting to understand what's happening.
Does you knob have an automation (even just one point)?
Are you using the Core Library LFO or another one?

[jdd]

as far as i know, no automation, no modulation, and yup the core library ones:



the track itself has a single speaker-off event and a small amount of volume automation

[jdd]

this is wild conjecture since I obviously have no idea how ableton is written but looking at a hex dump of the file i assume is storing an undo list, it looks like it may have grabbed a one or more values coming from the lfos while opening the set. part of how i figured out where the modified input gain knob was was noticing that a repeated number in the file was the same as the track number and that it sure kinda looked like a list of identifiers and values, plus the file doesn't exist prior to opening.

not sure if it'd be ok to post the dump here, but am glad to if it is/would be helpful